Which forms the core of microvilli?

• A. Microfilaments
• B. Microtubules
• C. Intermediate filaments
• D. Myosin

Answer: (A)

Microvilli are tiny, finger-like projections on the apical surface of many epithelial cells that increase surface area for absorption. Their structural backbone is a bundle of actin filaments (microfilaments) that runs the length of each projection. These actin filaments are cross-linked by actin-binding proteins and anchored to the cell’s terminal web, giving microvilli their rigid, slender shape and enabling rapid turnover during absorption. Microtubules would form the core of cilia or flagella, not microvilli; intermediate filaments provide general cellular structural support; myosin is a motor protein that interacts with actin to generate movement, not the core itself. Therefore, microfilaments are the best answer.